Description
vLLM through 0.29.0 fails to properly validate bad_words token indices against the model's generation output width in SamplingParams.update_from_tokenizer(). Attackers can supply out-of-bounds token indices that corrupt logits memory of concurrent requests, causing different in-flight HTTP requests to return incorrect tokens.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| vllm-project | vllm | ≤ 0.29.0 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | python-vllm | 0.30.0-1.1 | openSUSE-SU-2026:11867-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | vllm | < 0.30.0 | 0.30.0 | PYSEC-2026-4000 |
Advisories 2
- WID-SEC-2026-3483 vllm: Mehrere Schwachstellen ermöglichen Manipulation von Daten BSI CERT-Bund (WID) · Sep 27, 2026
- openSUSE-SU-2026:11867-1 python313-vllm-0.30.0-1.1 on GA media SUSE / openSUSE Security Updates · Sep 24, 2026
References
- GitHub PR #48824 issue-tracking patch
- _bad_words_kernel at v0.29.0 technical-description
- update_from_tokenizer at v0.29.0 technical-description
- https://github.com/vllm-project/vllm product
- VulnCheck Advisory: vLLM through 0.29.0 Cross-Request Logits Corruption via bad_words third-party-advisory